Explaining Private School Popularity in 1960 (!)

The prediction for each county is based on a linear regression using two variables: the population density of the county, and the percentage of familes with an income over $10,000. These two factors explain 78% of the observed variation in private school enrollment.

Only counties with at least 5,000 K-12 students were included. These counties represent 97.8% of all K-12 students in the state.
Source: 1960 US CensusGet the dataCreated with Datawrapper